I have a 2008 Prius with about 68,000 miles on it. A few days ago the red triangle came on and the MFD showed Oil Pressure warning. The light stayed on for about 20-30 seconds and then shut right off. It has done this 4 times so far. Right before the light started coming on the MAINT REQD light started flashing. We changed the oil yesterday, and my husband noticed it was slightly wet around the oil pan gasket (never has been before). The oil level was still normal before the oil change. The light only comes on when we stop (suddenly, like at a red light) and (so far) always shuts right back off. Any idea what could be causing it or how to fix it?
Your motor will quickly eat itself if the oil pressure is low. This is something that a dealer needs to look it. Are you sure you put a least 3 quarts of oil in?
Your engine's oil pressure apparently is low. This can cause permanent damage to the engine if allowed to continue. 1. Check the engine oil level when the car is level, and IG-OFF. It should be between the two dimples on the dipstick. 2. See if you can figure out exactly where the oil leak is coming from and if this provides a clue about the low oil pressure. If 1 and 2 do not produce any insights, then I recommend that you immediately have your car towed to your local Toyota dealer for assistance. Perhaps the engine oil pump or the oil pressure sender unit has a problem. I recommend strongly that you discontinue use of the car until this problem is figured out. Good luck.
Thanks for the help everyone We are still working on it. We changed the oil pressure sending unit and that didn't solve the problem. We priced oil pump at dealership about $200(if they install it would be $600 extra for labor), anyone know if we can find one online cheaper? Local parts stores are telling us this is a dealer only item.
That means it's definitely low oil pressure then. Make sure you don't drive the car like this, because it can seriously damage the engine very quickly. BTW. Thanks for the update and please let us know how it turns out. I don't recall anyone else here having that particular problem, so it will be interesting to know what it turns out to be.
Just another update. Sorry for the delay. We replaced the oil pump, and the light still comes on. The light comes on when the gas engine shuts off and the electric motor is the only one running(but it doesn't do it very often anymore, right after we replaced the oil pump it would come on at least 4-5 times per trip we took, then immediately shut back off when the gas engine kicked in). We are starting to think it is a false code coming up (some kind of electrical problem maybe?).
Arh, that's really significant information that puts a completely different slant on the problem! Since the engine doesn't even turn at speeds under 42MPH in EV mode, then yes that makes it much more likely to be some kind of electrical problem. Obviously when the engine isn't spinning then it wont produce any oil pressure (as the oil pump is still a regular mechanical type) so I'm guessing the software must disable the low oil pressure warning when the engine isn't spinning. Now the other possibility is that it only happens in EV mode at 42 MPH and above (or below 42MPH in the case of stage 3a operation) , in which case the engine is normally turning at only something like idle speed. In this case it really could indicate a loss of oil pressure due to worn bearings. So please see if you can determine if this happens in EV mode when the engine is turning or when the engine is off. This really makes a difference to the diagnosis.
BTW. Sorry about the jargon, stage 3a operation is where the Prius is running purely in EV mode but still the engine continues to run with fuel injection (very annoying I know but it's true, if you do a thread search you'll find lots of information these "stages" of hybrid operation). To detect this you'll need to either be really good at listening to the engine noise or else to have some way of detecting fuel injection. If this does turn out to be the problem (low oil pressure at idle even after changing the oil pump and sender) then one way to confirm the problem is real is to try a heavier oil. You could even go as heavy as 15W40 to test this, assuming that the weather in Ark is fairly warm this time of year. (Yeah I know the 0W20 fan club are probably going to jump all over me now hehe , but I'm serious about this). If this test "corrects" the problem then you were genuinely getting low oil pressure at low engine RPM, and it may indicate worn bearings. Obviously I'm assuming that you've already changed the oil filter with the oil.
Also, one more question jinkiesscoobygirl. What brand/grade oil are you currently using and have you mostly used in the past.
Take out the oil pressure switch and replace with an oil pressure gauge (from breakers if you do not have one) put car in maintenance mode and run engine till warm, oil pressure should be at idle above 4.2PSI at 2500RPM 22-80PSI. If pressure is low check oil pump release valve for sticking or for a weak or broken spring, after this if nothing is found I am afraid it will be bearings.
